The kitchen textile and bath towel industry is a very competitive, commodity-driven market, and suppliers are constantly striving to develop and produce different and unique products to attract consumers. This is currently done mainly through design and color.
Consumers perceive cotton as the most desirable fiber for toweling, based on its ability to absorb water 100% cotton products dominate the traditional towel market, where the 100% cotton content is used as a major selling feature. However, 100% cotton is typically lacking in softness, and is easily stained, so there is a need for a terry fabric that is extremely soft, absorbent and stain resistant. In addition, further improvement in absorbency properties of fabrics used for toweling is also desirable. This stain resistance is very important in both kitchen and bath toweling, where a cotton towel that easily stains is unattractive and, moreover, appears less than clean and sanitary, rendering it useless in certain applications, such as the hospitality and foodservice industries.
Microfibers are very thin fibers having a linear density of less than 1 denier per filament (dpf), making these fibers even finer than silk, which has a linear density of 1 dpf. Microfibers, also known as “microdenier fibers”, have silk-like properties, including the drape, flow, look, feel, movement, softness and luxuriousness of silk, which make the microfibers desirable in the fashion industry for making items such as intimate apparel, outerwear, and sportswear. Although similar to silk, synthetic microfibers also have the useful properties and performance imparted to and in common with certain man-made fibers. For example, synthetic microfibers tend to be easy to care for and often have “wash & wear” capability.
Microfibers are typically formed from composite fibers by processes well known in the art. Composite fibers are manufactured in general by combining at least two fiber-forming polymers via extrusion. One known method for producing split fiber structures includes the steps of forming fibrillizable or splittable multicomponent conjugate fibers into a fibrous structure and then treating the fibrous structure with an aqueous emulsion of benzyl alcohol or phenyl ethyl alcohol to split the composite fibers. Another known method has the steps of forming splittable conjugate filaments into a fibrous structure and then splitting the conjugate fibers of the fibrous structure by flexing or mechanically working the fibers in the dry state or in the presence of a hot aqueous solution. Yet another method for producing split fibers is a needling process. In this process, conjugate fibers are hydraulically or mechanically needled to fracture and separate the cross-sections of conjugate fibers, forming fine denier split fibers. FIG. 1 shows a cross-section of a splittable fiber with pie-shaped segment before splitting.
Microfibers composed of glass, polyolefin, polyester, polyamide, and cellulosic materials have been described in the patent literature. For example, U.S. Pat. No. 3,700,545 discloses a multi-segmented (i.e., multilayered) polyester or polyamide fiber having at least 10 fine segments (layers) with cross sectional shapes and areas irregular and uneven to each other. The spun fibers are treated with an alkali or an acid to decompose and remove at least a part of the polyester or polyamide. U.S. Pat. No. 3,382,305 discloses a process for the formation of microfibers having an average diameter of 0.01 to 3 microns by blending two incompatible polymers and extruding the resultant mixture into filaments and further dissolving one of the polymers from the filament. U.S. Pat. No. 5,120,598 describes ultra-fine polymeric fibers for cleaning up oil spills. The fibers were produced by mixing a polyolefin with polyvinyl alcohol and extruding the mixture through a die followed by further orientation. The polyvinyl alcohol is extracted with water to yield ultra-fine polymeric fibers. EP-A-498,672 discloses microfiber-generating fibers of island-in-the-sea type obtained by melt extrusion of a mixture of two polymers, whereby the sea polymer is soluble in a solvent and releases the insoluble island fiber of fineness of 0.01 denier or less. Described is polyvinyl alcohol as the sea polymer. U.S. Pat. No. 4,233,355 discloses a separable unitary composite fiber comprised of a polyester or polyamide which is insoluble in a given solvent and a copolyester of ethylene terephthalate units and ethylene 5-sodium sulfoisophthalate units, which is soluble in a given solvent. The composite fiber was treated with an aqueous alkaline solution to dissolve out at least part of the soluble polymer component to yield fine fibers. The cross sectional views of the composite fibers show an “islands-in-the-sea” type, where the “islands” are the fine fibers of the insoluble polymer surrounded by the “sea” of the soluble polymer.
U.S. Pat. No. 6,247,505 and DE 4200278 disclose a terry fabric wherein the carrier fabric is composed of cotton fiber, with cotton loops extending from one side and polyamide microfiber loops extending from the other side. The fabric is intended for use as a towel or bathrobe, and the U.S. patent states “when processed into a towel or bathrobe, they readily absorb the moisture on the skin of the user and transfer it to the outside” (col 3, lines 65–67). Such a fabric is not suitable for use as a kitchen or bath towel, since it is undesirable for liquid absorbed when wiping a hard surface to pass through the towel to the opposite surface, wetting the hand of the user Accordingly, there is a need for a terry fabric that wicks moisture away from a point of contact with a liquid on a hard surface to the interior of the towel, and spreads the moisture throughout the cotton ground fabric in both longitudinal and horizontal directions. There is also a need for a terry fabric for use in toweling that absorbs water quickly and holds the water away from all surfaces of the towel.